The present invention relates to a blank for producing a soft wall inside socket of a prosthesis comprising a pre-shaped side wall formed of a thermoplastic material, an inside liner and an outside sheathing, the blank forming a receiving space for receiving a shank stump or lower leg stump, having an opening restricted by an edge of the side wall for inserting the shank stump.
Such a blank is known from the U.S. Pat. No. 4,635,626.
A blank for a soft wall inside socket is known consisting of a thermoplastic material. The blank is pre-shaped such that it forms a receiving space having an opening restricted by an edge for receiving a shank stump. On the inner side of the receiving space a liner is provided made of body compatible material. At the outer side a sheathing of wear resistant material is deposited. The liner and the sheathing are sewn to each other at the edge of the opening such that the edge is formed rounded. For individually adapting the blank to a shank stump of an amputee the blank is heated to about 80.degree. C. The blank is pushed onto the shank stump and applied with excess pressure in a known manner. Thereby, the blank is precisely adapted to the individual shank stump. After cooling of the blank it keeps its form so that the soft wall inside socket is completed.
The above-described blank has the disadvantage that in a normally necessary adaption of its length along the shank stump the edge cannot be perfectly closed because of the thickness of the thermoplastic material, which can lead to substantial drawbacks during wearing.